<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <script src="jquery.js"></script>
    <script>
    Promise.all([
      $.ajax({url: 'data/arr.txt', dataType: 'json'}),
      $.ajax({url: 'data/json.txt', dataType: 'json'})
    ]).then(function(results){
          let[arr,json] = results;
          alert('success');
          console.log(arr,json);
    }, function(err){
      alert('fail ' + err);
    });


    </script>
  </head>
  <body>

  </body>
</html>
